Overview: BAC Mono
Sibling engineers Neill and Ian Briggs have not only designed their own car, they have put it into production. The Mono is a single-seat sportscar that can be used on the road or the track, and the brothers’ company — the Briggs Automotive Company (BAC), not unreasonably — is set to sell between 50 and 100 examples a year at a price of around £80,000.
As you may have guessed from the price, the Mono emphatically does not fall into the amusing-but-crude category. The Briggs brothers are real-life consultant automotive engineers whose clients include Ford, Porsche and Daimler. The Mono has technology enough to produce fatal apoplexy in a Caterham Seven owner: the body is fabricated from a CFRP foam sandwich, for example, while the car’s aerodynamics were developed using computational fluid dynamics at Stuttgart University.
As we have mentioned, the Mono is built from a carbon-fibre sandwich. The CFRP is produced using a vacuum resin infusion process by Canadian carbon-fibre specialist Apex Composites of Ontario. The body features a TIG-welded, cold-drawn seamless tube steel driver safety cell, complete with FIA-compliant roll-over protection system — similar in concept to a DTM race car. The side structure has been designed to absorb impacts, and there is a carbon-fibre ‘crash-box’ at the front.
Power is supplied by an atmospheric four-cylinder 2.3-litre Cosworth engine rated at 280PS. The engine is mounted longitudinally, and mated to an electronically-controlled, paddle-shift, six-speed sequential Hewland transmission; perforce, a limited-slip differential is fitted. The rose-jointed, aero-profiled pushrod suspension features adjustable Sachs Racing dampers. Components for the braking system are supplied by AP Racing; wheels are bespoke HRT items made by OZ Racing, shod with street-legal Kumho track tyres — also bespoke. The car’s electronics and instrumentation are by GEMS.
A full six-point racing harness is supplied by Willans. There is a secure locker in which to store a helmet and the detachable steering wheel when the car is parked.
The carbon-fibre driver’s seat — the only seat — is fixed, both for safety and for what BAC sees as the optimum weight distribution — 48:52 front:rear. Drivers of varying shapes and sizes can be accommodated by adjusting the pedal box and steering column. An F1-style fully-profiled seat is an optional extra.
Cosworth’s power-unit is markedly undersquare — odd for such a high-revving engine. It is a dry-sump unit with forged con. rods and pistons. Roller barrel port throttles are used.
The six-speed sequential Hewland FTR transmission is fully stressed and incorporates the oil tank for the engine. The gearbox itself has conventional splash lubrication. Gearchanges are carried out electropneumatically, with paddle switches mounted on the steering-wheel.
Running-gear leaves nothing wanting. At the front is an adjustable pushrod-activated double-wishbone arrangement with bell-cranks mounted on needle roller bearings. Rising-rate springs, Ackermann geometry and wheel camber adjustable by shims complete the picture.
The rear suspension has the same layout and is mounted on the gearbox.
The wishbones are of TIG-welded seamless CFS3 steel aero tube; uprights are ultra light billet aluminium. Two-way adjustable Sachs racing RDS 36 formula system dampers are used, while springs are to race specification: H & R 325lb front and 375lb rear with rising rate jounce rubbers. Both front and rear anti-roll bars are adjustable.
Brakes use AP Racing components. Four-piston radial calipers are deployed front and rear, while all four discs are 295mm items — ventilated and cross-drilled with billet machined mounting bells.
BAC’s web-site can be found here.
Briggs Automotive Company Ltd.
Unit 3b Holmes Chapel Business Park
Cheshire CW4 8AF
— Final drive